Sure, there are several options. Some may depend on the overall range
of the IR source in your iPAQ, I don't know what the range is but on a
Dell Axim it's about 30 feet / 10 metres.

I like Vito Remote (enough to buy it, I mean !)
http://vitotechnology.com/en/products/remote.html

They just released a new version with several improvements. I'll be
getting the new update later today - thx for the reminder.

Other people will chime in with alternatives, its all a matter of
taste, user interface and skin selections, as they perform essentially
the same functions.

I haven't found anything Vito can't control yet - even our works
Aircon unit - with comedy value for the guy sitting under it as you
turn it down to 5ºC !

Whichever package you get, I don't think there are full 'free
versions' with any remote control programs, so expect to pay about
$10. Compare that with the cost of a colour, touch-screen learning
remote (about $120-200) and you're ahead by a long way !

Cheers - Neil